The present invention relates generally to depassivating a battery in an electronic device and, more particularly, to depassivating a battery using functional hardware already present in the device at times when the functional hardware is not performing a normal operation.
Batteries are used as a power source for a variety of different functional devices. Many batteries, such as lithium batteries, have a long shelf life and are able to power a functional device for an extended period of time. The life of the batteries may be further extended when the device has a standby mode that draws very little current from the battery when the device is not performing functional operations, or is otherwise operating in a low-current state.
One aspect of lithium and certain other types of batteries is the formation of a passivation layer that forms through a reaction between the metal anode and cathode. The passivation layer is a resistance layer that builds up over time that prevents or reduces internal discharge of the battery thus allowing for a longer shelf life. The passivation layer may also build up faster when the battery is exposed to a high environmental temperature. A disadvantage of the passivation layer is that the battery exhibits a drop in initial available voltage when the battery is first used after a standby period. The initial available voltage may not be adequate to properly power the device causing the device to shut down or abort specific normal operations performed by the device.